Expression and clinical significance of p120 catenin mRNA and protein in pancreatic carcinoma

p120-Catenin Downregulation and PIK3CA Mutations Cooperate to Induce Invasion through MMP1 in HNSCC

Despite recent improvements in treatment for head and neck squamous cell carcinoma (HNSCC), half of all patients with a regional or advanced disease will die within 5 years from diagnosis. Therefore, identification of mechanisms driving the aggressive behavior of HNSCC is of utmost importance. Because p120-catenin (CTNND1/P120CTN) downregulation and PIK3CA mutations are commonly found in HNSCC, the objective of this study was to identify their impact on fundamental processes of metastasis, specifically, migration and invasion. Furthermore, this study aimed to identify the key effector proteins regulated by P120CTN downregulation and PIK3CA mutations. Studies using oral keratinocytes demonstrated that P120CTN downregulation and PIK3CA mutations increased migration and invasion. In addition, P120CTN downregulation and PIK3CA mutations resulted in elevated matrix metallopeptidase 1 (MMP1) levels. Inhibition of MMP1 resulted in decreased invasion, suggesting that MMP1 plays a critical role in HNSCC invasion. Moreover, analysis of HNSCC patient specimens from The Cancer Genome Atlas confirmed these findings. Tumors with low P120CTN and PI3K pathway mutations have higher levels of MMP1 compared to tumors with high P120CTN and no PI3K pathway mutations. In conclusion, this study demonstrates that P120CTN downregulation and PIK3CA mutations promote MMP1-driven invasion, providing a potential novel target for limiting metastasis in HNSCC.Implications: Because of its role in invasion, MMP1 represents a novel, potential target for limiting metastasis in a subset of HNSCCs with P120CTN downregulation and PIK3CA mutations. Mol Cancer Res; 15(10); 1398-409. ©2017 AACR.

CTNND1 755 T>G Promoter Polymorphism and Risk of Pancreatic Carcinoma in Chinese

OBJECTIVE

To investigate the relationship between 755 T>G polymorphisms in the CTNND1 gene, which is associated with the risk of pancreatic carcinoma in Chinese.

METHODS

CTNND1 755 T>G genotypes were determined by PCR-RFLP in 122 pancreatic carcinoma patients and 180 healthy controls matched for age and sex, who did not receive radiotherapy or chemotherapy for newly diagnosed and histopathologically confirmed pancreatic carcinoma.

RESULTS

In control subjects, the frequency of T/T and G/T genotypes, and T and G alleles was 79.4%, 17.2%, 88.1%, and 11.9%, respectively. The distribution of genotypes and allelotypes in the pancreatic carcinoma patients was significantly different from that in the controls (P = 0.007, P = 0.012). Combined GG and GT genotypes were found to have a higher OR in male pancreatic carcinoma patients and the group under the age of 70 years (males: OR, 1.409; 95%CI, 0.912~1.921; under 70 years: OR 1.626; 95% CI, 0.878~2.312). This study also showed a distinct difference in the distribution of P120ctn and single nucleotide polymorphisms (SNPs) between Chinese and Canadian (11.9% vs. 3.9%, P = 0.008).

CONCLUSION

CTNND1 755 T>G polymorphism may be a stratification marker to predict the susceptibility to pancreatic carcinoma, at least in Chinese. CTNND1 promoter SNPs is diverse in ethnic populations.

p120 Catenin Suppresses Basal Epithelial Cell Extrusion in Invasive Pancreatic Neoplasia

Aberrant regulation of cellular extrusion can promote invasion and metastasis. Here, we identify molecular requirements for early cellular invasion using a premalignant mouse model of pancreatic cancer with conditional knockout of p120 catenin (Ctnnd1). Mice with biallelic loss of p120 catenin progressively develop high-grade pancreatic intraepithelial neoplasia (PanIN) lesions and neoplasia accompanied by prominent acute and chronic inflammatory processes, which is mediated, in part, through NF-κB signaling. Loss of p120 catenin in the context of oncogenic Kras also promotes remarkable apical and basal epithelial cell extrusion. Abundant single epithelial cells exit PanIN epithelium basally, retain epithelial morphology, survive, and display features of malignancy. Similar extrusion defects are observed following p120 catenin knockdown in vitro, and these effects are completely abrogated by the activation of S1P/S1pr2 signaling. In the context of oncogenic Kras, p120 catenin loss significantly reduces expression of genes mediating S1P/S1pr2 signaling in vivo and in vitro, and this effect is mediated at least, in part, through activation of NF-κB. These results provide insight into mechanisms controlling early events in the metastatic process and suggest that p120 catenin and S1P/S1pr2 signaling enhance cancer progression by regulating epithelial cell invasion. Cancer Res; 76(11); 3351-63. ©2016 AACR.

p120 catenin is required for the stress response in Drosophila

p120ctn is a ubiquitously expressed core component of cadherin junctions and essential for vertebrate development. Surprisingly, Drosophila p120ctn (dp120ctn) is dispensable for adherens junctions and development, which has discouraged Drosophila researchers from further pursuing the biological role of dp120ctn. Here we demonstrate that dp120ctn loss results in increased heat shock sensitivity and reduced animal lifespan, which are completely rescued by ectopic expression of a dp120ctn-GFP transgene. Transcriptomic analysis revealed multiple relish/NF-κB target genes differentially expressed upon loss of dp120ctn. Importantly, this aberrant gene expression was rescued by overexpression of dp120ctn-GFP or heterozygosity for relish. Our results uncover a novel role for dp120ctn in the regulation of animal stress response and immune signalling. This may represent an ancient role of p120ctn and can influence further studies in Drosophila and mammals.

Expression of P120 catenin, Kaiso, and metastasis tumor antigen-2 in thymomas

Thymomas of the same histological subtype sometimes manifest different biological behaviors. Metastasis Tumor Antigen-2 (MTA2) is targeted by the transcriptional repressor Kaiso, the distribution which is thought to be modulated by p120catenin (p120ctn). It is currently unclear if expression of p120ctn, Kaiso, and MTA2 relates to the biological behavior of thymoma. P120ctn, Kaiso, and MTA2 expression were examined in 137 cases of thymoma, three cases of thymic carcinoma, and 18 paired autologous normal thymic tissues using immunohistochemistry, and correlation of these proteins with histological subtypes and clinical stages were analyzed. In normal thymic epithelial cells, p120ctn was expressed on the cell membrane but Kaiso and MTA2 were not detected. Membranous p120ctn expression was reduced in thymoma epithelial cells, while ectopic cytoplasmic expression was observed in 76.6 % (105/137) of the cases. Cytoplasmic Kaiso was detected in 69.3 % (95/137) and nuclear MTA2 was detected in 70.8 % (97/137) of the thymomas. There were good consistencies (Kappa = 0.559, 0.512, 0.652; all P < 0.001) and correlations (r = 0.733, 0.652, 0.708; all P < 0.001) between cytoplasmic p120ctn, cytoplasmic Kaiso, and nuclear MTA2 expression in thymomas. All three protein factors correlated with histological type and clinical stage in thymoma (P < 0.05). Specifically, cytoplasmic p120ctn and Kaiso expression and nuclear MTA2 expression were higher in high-risk (types B2 and B3) thymomas and Masaoka stage III/IV thymomas than low-risk (types A, AB, and B1) and stage I/II thymomas (both P < 0.001), respectively. Cytoplasmic p120ctn, cytoplasmic Kaiso, and nuclear MTA2 expression correlated directly with histological type and Masaoka stage and may thus be used as potential biomarkers to predict biological behavior of thymoma.